Neurobiology: Neurotransmitters, Receptors and Autonomic Nervous System - Test 3

Helpfulness: +1
Set Details Share
created 9 years ago by lifesurfeit
324 views
book cover
From Neuron to Brain
Chapters 4, 5, 7, 13-17, 23, 27
test April 5th
updated 9 years ago by lifesurfeit
Grade levels:
College: First year, College: Second year, College: Third year, College: Fourth year
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:
1

Transporter protein

A membrane protein that transports neurotransmitters, or their precursors, across membranes to concentrate them in either presynaptic cytosol or synaptic vesicles.

2

Ion pump

A protein that transports ions across a membrane at the expense of metabolic energy.

3

Depolarization

A change in membrane potential, taking it from the value at rest (e.g., 65 mV) to a less negative value (e.g., 0 mV). Rising curve (more positive)

4

Hyperpolarization

The last part of an action potential, also called
undershoot. The part of an action potential when the membrane potential is more negative than at rest. Tends to reduce excitability.

5

Ion channel

A membrane-spanning protein that forms a pore that allows the free passage of ions from one side of the membrane to the other.

6

Patch clamp recording

A method that enables an investigator to hold constant the membrane potential of a patch of
membrane while current through a small number of
membrane channels is measured.

7

Resting membrane potential (Vm)

The difference in electrical charge across the membrane, or membrane voltage, maintained by a cell when it is not generating action potentials; also called resting potential. Neurons have a resting membrane potential of about 65 mV.

8

Tetrodotoxin (TTX)

A toxin that blocks Na permeation through voltage-gated sodium channels, thereby blocking action potentials.

9

Action potential

A brief fluctuation in membrane potential caused by the rapid opening and closing of voltage-gated ion channels; also known as spike, nerve impulse, or discharge. ___s sweep like a wave along axons to transfer information from one place to another in the nervous system.

10

Inhibitory postsynaptic potential (IPSP)

A change in the postsynaptic membrane potential by the action of a synaptically released neurotransmitter, making the postsynaptic neuron less likely to fire action potentials. Caused by synaptic activation of glycine-gated or GABA-gated ion chanels. (Cl- in)

11

Excitatory postsynaptic potential (EPSP)

Depolarization of the postsynaptic membrane potential by the action of a synaptically released neurotransmitter. Caused by synaptic activation of ACh-gated and glutamate-gated ion channels. (Na+ in)

12

Capacitative current

A transient current that flows across the cell membrane in response to voltage change, thereby recharging the membrane capacitance to the new membrane potential. Applied experimentally to restore/change the resting membrane potential.

13

Absolute refractory period

The period of time, measured from the onset of an action potential, during which another action potential cannot be triggered, until the membrane potential goes sufficiently negative to reactivate the channels.

14

Summation

A simple form of synaptic integration whereby excitatory postsynaptic potentials generated at more than one synapse on the same cell combine to produce a larger postsynaptic depolarization.

15

Threshold

A level of depolarization sufficient to trigger
an action potential.

16

Facilitation/Potentiation

An increase in evoked release of transmitter from nerve terminals, due to previous synaptic activity; can last for several hundred ms.

17

Depression

An decrease in evoked release of transmitter from nerve terminals, due to previous synaptic activity; can last for several hundred ms.

18

Long-term potentiation (LTP)

A long-lasting enhancement of the effectiveness of synaptic transmission that follows certain types of conditioning stimulation (lasts hours).

19

Long-term depression (LDP)

A long-lasting decrease in the effectiveness of synaptic transmission that follows certain types of conditioning stimulation (lasts hours), such as repeated inhibitory or hyperpolarizing stimulus.

20

Desensitization

Reduction of the response of a receptor to a ligand after prolonged or repeated exposure.

21

Nernst equation

A mathematical relationship used to calculate an ionic equilibrium potential.

Eion = 58/z log [out]/[in]

22

vSNARE

Complementary peptide protein embedded in membrane of vesicle that allows vesicle to dock close to presynaptic membrane.

23

tSNARE

Complementary peptide protein embedded in membrane of target neuron that allows vesicle to dock close to presynaptic membrane.

24

Exocytosis

The process whereby material is released from an intracellular vesicle into the extracellular space by fusion of the vesicle membrane with the cell membrane.

25

Synaptic cleft

The region separating the presynaptic and postsynaptic membranes of neurons.

26

Synaptic vesicle

A membrane-enclosed structure, about 50 nm in diameter, containing neurotransmitter and found at a site of synaptic contact.

27

Quantal release

Secretion of multimolecular packets (quanta) of neurotransmitter by the presynaptic nerve terminal.

28

Clathrin coated pit

Vesicles associated with the cystolic protein. Form domains of the plasma membrane termed ___, which concentrate large extracellular molecules that have different receptors responsible for the receptor-mediated endocytosis of ligands.

29

Endocytosis

The process by which a bit of the cell membrane is pinched off, internalized, and converted to an intracellular vesicle (endosome).

30

Reuptake

Reabsorption of a neurotransmitter by a neurotransmitter transporter of a pre-synaptic neuron after it has performed its function of transmitting a neural impulse. Allows for the recycling of neurotransmitters and regulates the level of neurotransmitter present in the synapse and controls how long a signal resulting from neurotransmitter release lasts.

31

Autonomic nervous system

A system of central and peripheral nerves that innervates the internal organs, cardiovascular system, and glands; also called visceral PNS. The ___ consists of sympathetic, parasympathetic, and enteric divisions.

32

Preganglionic

A neuron of the sympathetic and parasympathetic divisions of the autonomic nervous system; its cell body lies in the CNS (spinal cord or brain stem), and its axons extend peripherally to synapse on postganglionic neurons in the autonomic ganglia.

33

Postganglionic

A peripheral neuron of the sympathetic and parasympathetic divisions of the autonomic nervous system; its cell body lies in autonomic ganglia, and its axons terminate on peripheral organs and tissues.

34

Sympathetic

A division of the autonomic nervous system that in fight-or-flight situations activates physiological responses, including increased heart rate, respiration, blood pressure, and energy mobilization and decreased digestive and reproductive functions; its peripheral axons emerge from the thoracic and lumbar spinal cord.
Pre G mACh -> Norepinephrine Post G neuron

35

Parasympathetic

A division of the autonomic nervous system that maintains heart rate and respiratory, metabolic, and digestive functions under normal conditions; its peripheral axons emerge from the brain stem and sacral spinal cord.
Local ganglia near target tissue. Pre nACh -> mACh Post G neuron

36

Enteric

A division of the autonomic nervous system that innervates the digestive organs; consists of the myenteric (smooth muscle) and submucous (connective tissue) plexuses.

37

Acetylcholine synthesis

choline acetyltransferase

38

Acetylcholine degradation

acetylcholinesterase

39

GABA synthesis

glutamic acid decarboxylase

40

GABA degradation

(1) GABA alphar-oxoglutarate transminase and (2) succinic semialdehyde dehydrogenase

41

Glutamate synthesis

glutaminase

42

Glutamate degradation

glutamine synthetase

43

Dopamine synthesis

(1) tyrosine hydroxylase and (2) aromatic L-amino acid decarboxylase

44

Dopamine degradation

MAO (then ADH or AR and COMT) or (1) COMT and (2) MAO (then AR/ADH)

45

Norepinephrine synthesis

Dopamine B-hydroxylase

46

Epinephrine synthesis

phenylethanolamine N-methyltransferase

47

Norepinephrine/Epinephrine degradation

MAO or via COMT

48

Serotonin synthesis

(1) tryptophan-5-monooxygenase (2) aromatic L-amino acid decarboxylase

49

Serotonin degradation

(1) monoamine oxidase (2) aldehyde dehydrogenase or aldehyde reductase

50

Histamine synthesis

histidine decarboxylase

51

Histamine degradation

(1) diamine oxidase and (2) aldehyde dehydrogenase
OR (1) histamine methyltransferase (2) MAO and (3) aldehyde dehydrogenase

52

Aldehyde -> Alcohol

Aldehyde reductase

53

Aldehyde -> acid

Aldehyde dehydrogenase

54

Amine degradation

Monoamine oxidase

55

Catechol degradation

COMT (catechol O-methyltransferase)

56

Monoamine oxidase (MAO)

enzyme in many neurotransmitter degradation processes

57

Orexin

Hypothalamic neuropeptides that regulate sleep and feeding; aka hypocretins.

58

NO

Nitric oxide; a gaseous molecule proposed for intercellular communication. May be a retrograde messenger that is smaller and membrane permeable. Breaks down quickly.

59

Glycine

Transmitter released at many inhibitory synapses in the spinal cord and brainstem.

60

Enkephalins

Small neuropeptides comprising five amino acids that act on opioid receptors.

61

Axonal transport

Term for movement of proteins, intracellular particles and organelles along axons.

62

Voltage activated channel

A channel that is activated or inactivated by changes in membrane potential.

63

Ligand gated ion channel

A channel that is activated by binding an ion or molecule to an external or internal receptor region of the channel.

64

Ionotropic receptor

An ion channel that is opened by a neurotransmitter or other chemical ligand (i.e. nicotinic ACh receptor)

65

Metabotropic receptor

A neurotransmitter receptor that interacts with another membrane protein such as G protein to produce its effect on the neuron; can trigger widespread metabolic effects.

66

NMDA

GluN1 - four subunits, 2 Glu binding, 2 Gly binding
Can also bind aspartate and D-serine respectively
Transmitter and voltage activated; permeable to Ca++; slower turnover

67

Metabotropic Glutamate receptors

Multispan G protein-coupled receptors, 7 TM domains; play a role in late LTP using G protein signaling

68

AMPA

GluN2 - four subunits, 2 Glu binding, 2 Gly binding
Translocated from latent pool to synapse
Permeable to Na+ and K+
Phosphorylation by CaMKII during LTP changes their conformation, increases their conductance to Ca++

69

Glutamate receptors

1) AMPA, 2) NMDA and 3) Kainate

70

Nicotinic

Ionotropic- AChR, ligand-gated ion channels-pentameric-10 human alpha subunits, 4 beta subunits, plus 1 each delta, epsilon and gamma.-Cys loop superfamily- fast acting

71

Muscarinic

Metabotropic AChR G-protein coupled-induce signaling changes that release intracellular Ca++, slower in action

72

ACh receptors

Muscarinic and Nicotinic

73

Histamine receptors

H1, H2, H3. Work as G protein coupled receptors. Broad projections from tuberomammillary nucleus underlie a role in sleep/wake cycles and motor control.

74

Serotonin receptors

5HTR1-5 - respond to raphe nuclei projections, Mediate mood, behavior, wakefulness, attention, (aggression in some species)
Mostly metabotrpic (GPCR's), few ionotropic
Multispan transmembrane receptors

75

Dopamine receptors

D1, D5 - activate adenylate cyclase
D2-D4 - inhibit adenylate cyclase

76

Noradrenergic receptors

alpha & beta subunits
Locus coerulus projections and auto innervation to control firing rate (negative feedback loop)

77

Tactile perception

Activation of primary somatosensory cortex and central sulcus, other sulci, primarty motor cortex, medial premotor cortex, prefrontal cortex, posterior parietal cortex, etc
Damage results in agnosia (inability to recognize objects) or neglect syndrome (ignored body part)

78

Visual perception

Ventral pathway in object recognition and dorsal pathway for motion perception.
Activation of primary visual cortex (V1), V2, V4, temporal cortex, fusiform face area (ventral), central sulcus, medial temporal and medial superior temporal areas (dorsal).

79

Synaptotagmin

Vesicle protein that is triggered by Ca++ to induce vesicle fusion, inducing interaction between tSNARE and vSNARE proteins for vesicular docking.

80

Synaptic plasticity

The bility of the connection, or synapse, between two neurons to change in strength in response to either use or disuse of transmission over synaptic pathways.